Emission accounts Julian Chow United Nations Statistics Division 26-30 September 2016 Putrajaya, Malaysia
SEEA Conceptual Framework
Types of physical flows accounts in SEEA-CF Physical flow accounts Topics covered (detailed definition) Full set of supply and use tables for materials Economy-wide material flow accounts (MFA) Physical supply and use tables for water (PSUT water) Physical supply and use tables for energy (PSUT energy) All resources and materials (energy, water, air emissions, water emissions, solid waste) (CF 3.45) Supply and consumption of energy; air emissions, water emissions, and solid waste (CF 3.279) Supply (precipitation) and consumption of water (CF 3.186) Supply and consumption of energy (CF 3.140) Air emissions accounts Air emissions (CO2, pollutants) (CF 3.233) Water emissions accounts Water emissions (CF 3.257) Waste accounts Solid wastes (CF 3.268) CF = Central Framework, white cover edition, refers to paragraph number
Similarities and differences of various physical flows account in SEEA-CF Similarities: > Scope includes Flows from the environment to economy (natural inputs) Flows within the economy (Products flow) Flows back to environments (Residuals flows) > Finer level of focus can be undertaken consistent with the general principles of the PSUT > Same concepts, definitions and standards > Same institutional units Differences: > Units of measurement > Key components of the PSUT > Breakdowns of economic activities
What do water emission accounts measure? Present information on the activities responsible for the emissions and releases, the types and amounts of substances, as well as the destination of the emissions (e.g. water resources or the sea). Describe, in physical units, flows of pollutants added to wastewater as a result of production and consumption, and flowing into water resources either directly or through the sewage network.
Why compiling water emission accounts Emission accounts provide information on > Which activities are responsible for the emission > How much is being emitted > Where is being emitted They are useful for designing policies aimed at reducing pressure on the environment
Why compiling water emission accounts Since they are linked to the economic accounts, they allow for > the formulation of cost-effective policies aiming at reducing emissions > the evaluation of the economic impacts of policies aiming at reducing emissions Useful tool for designing economic instruments, including new regulations to reduce emissions into the inland water system or seas and oceans
Emission to water Substances released to water resources by establishments and households as a result of production, consumption and accumulation process Flows
Flows in water emission account
Wastewater and pollutants pathways Households Agriculture Other industries Rest of the world Sewerage Water resources and the sea
Water emission accounts: coverage Record the quantity of substance added to water by establishment and households during an accounting period Cover > Substances added to wastewater and collected in the sewage system > Substances added to wastewater and discharged directly to water bodies > Substances from non-point sources E.g. emissions from urban runoff and emissions from agriculture
Water emission accounts: Key components Emission by types of substances (supply) and received by the environment (use) > Direct flow to the environment Release to (supply) and collection by (use) economic units > Flow to sewage industry
Physical supply table for gross releases of substances to water Generation of gross releases to water Sewerage industry Other industries Households Accumulation Emissions from fixed assets Flows with the rest of the world Flows from the environment Total supply Emissions by type of substance BOD / COD * 5 594 11 998 2 712 20 304 Suspended solids Heavy metals Phosphorous 836 1 587 533 2 956 Nitrogen 10 033 47 258 1 908 59 199 Releases to other economic units BOD / COD * 7 927 8 950 16 877 Suspended solids Heavy metals Phosphorous 814 6 786 7 600 Nitrogen 15 139 30 463 45 602 Physical use table for gross releases of substances to water Collection of gross releases to water Flows with the rest of the world Flows to the environment Total use Sewerage Other Households industry industries Emissions received by the environment BOD / COD * 20 304 20 304 Suspended solids Heavy metals Phosphorous 2 956 2 956 Nitrogen 59 199 59 199 Collection by other economic units BOD / COD * 16 877 16 877 Suspended solids Heavy metals Phosphorous 7 600 7 600 Nitrogen 45 602 45 602 PSUT for water emission
Example of pollution flows in the economy Pollution expressed in thousands of metric tons of BOD5 per year The diagram shows that 106 units of pollution (measured in thousands of metric tons of BOD 5 per year) were released by economic activities and households. Wastewater Treatment Plants (WWTPs) removed 68 units, and 4 units were included in wastewater that was supplied for further use in the economy. Only 34 units of pollution were part of the emissions (emissions are releases to the environment).
Example of pollution flows in the economy Further disaggregation of the data is possible, as shown in the figure below. households release 91 thousand metric tons of BOD5 to the sewers Industries and services release 15 thousand 106 thousand metric tons of BOD5 is collected in sewers, but only 28 thousand are released to the environment (emissions) Industries and services release 6 thousand metric tons of organic pollution to the environment. In summary, the total emissions are 34 thousand tons of organic pollution (28 from sewerage + 6 from industries).
Example of pollution flows in the economy
Example Supply table
Agriculture, ISIC 01-03 Industry and services ISIC 05-99, except 3510, 36, and 37 Hydroelectricity, ISIC 3510 Thermoelectricity, ISIC 3510 Water Supply (drinking water), ISIC 36-A Water Supply (irrigation water), ISIC 36-B Sewerage, ISIC 37 Households Environment Total Example Use table Emissions by test or parameter Releases within the economy BOD 5 34 34 BOD 5 4 106 110 4 0 0 0 0 0 106 0 34 144
Sources Two sources > Point sources emission > Non-point (or diffuse) source Point sources emission > Geographical location of the discharge of the wastewater is identified > E.g. emissions from sewage facilities, power plants, industrial establishments > They are generally easier to measure since the point of emission to the water resources is clearly identified
Sources Non-point (or diffuse) sources > Sources without a single point of origin or a specific outlet into a receiving water resources > Pollutants are generally carried off the land by stormwater run-off or may be the result of a collection of individual and small scale polluting activities which for practical reasons cannot be treated as point sources of pollution. > Commonly used categories for non-point sources include agriculture and urban areas. > E.g. Urban runoff, releases from individual and small scale activity
Urban runoff Urban run-off: that portion of precipitation on urban areas that does not naturally percolate into the ground or evaporate, but flows via overland flow, underflow, or channels or is piped into a defined surface water channel or a constructed infiltration facility. It is generally highly polluted and there is an increasing awareness in the potential danger of discharging it into the environment without treatment. Emissions to water in the urban runoff are allocated to the Sewerage industry, ISIC 37 since this is the economic unit responsible for its collection and discharge
Basic concepts and definitions Gross emissions are the pollutants added to the water by an activity, assessed at the point where the wastewater leaves the activity's site (or the dwelling, in the case of households). Net (or final) emissions correspond to the pollutants discharged into water resources after treatment. Net emissions= gross emissions if there is no treatment of wastewater
Reallocation of emissions In the calculation of net emissions, the release of pollutants by the sewerage industry has to be reallocated to the economic unit responsible for the discharge in the first place Net emission = direct emission to the environment + share of emissions released to the environment by sewage industry Reallocation of emission > Use average removal rates (e.g. per category of WWTP) or > Use information of known removal rates per WWTP
Emission accounts Industries, households and the rest of the world are identified by columns They record the pollution added to water by an economic unit (and not the total pollution discharged with wastewater)
Scope of emission accounts Point sources: Include: Pollutants added to wastewater Exclude: Discharges of heavy metal and hazardous wastes not contained in wastewater (included in the SEEA waste accounts) Pollutants resulting from in-situ use (e.g. navigation, fishing, etc.) Non-point sources: Urban runoff Irrigation water and rain-fed agriculture All non-point sources except for urban runoff, irrigation water and rain-fed agriculture
Water emission accounts: - Inclusion and exclusion Do not include imports and exports of substances through natural flows of water resources > Substances in rivers crossing country borders are not included Included in the accounts are emissions of relevant substances from fixed assets, such as from vessels operating within a country s water resources. Include emission due to activities undertaken in water resources or seas
Households Rest of the world Total Emission accounts - Gross emissions tonnes Industries (by ISIC categories) Pollutant 1. Gross emissions (=1.a+1.b) 1.a. Direct emissions to water (=1.a.1+1.a.2=1.a.i+1.a.ii) 1.a.1 Without treatment 1.a.2 After on-site treatment 1.a.i To water resources 1.a.ii To the sea 1.b. To Sewerage (ISIC 37) 1-3 30 25 5 5-33, 41-43 35 36 37 38,39, 45-99 Total 185 90 95 Households 185 Agriculture 30 Other industries Rest of the world 90 95 25 5 Sewerage 20 Water resources and the sea
Emission accounts Emission by ISIC division 37 Pollutant 4. Emissions to water (=4.a+4.b) 4.a After treatment To water resources To the sea tonnes ISIC 37 20 20 Households 185 95 90 25 Agriculture 30 5 Sewerage Other industries 20 Rest of the world 4.b Without treatment To water resources Water resources and the sea To the sea Now we can reallocate the emissions by ISIC 37 to the activity responsible for the emission
Households Rest of the world Total Emission accounts net emissions tonnes Industries (by ISIC categories) Pollutant 1. Gross emissions (=1.a+1.b) 1.a. Direct emissions to water (=1.a.1+1.a.2=1.a.i+1.a.ii) 1.a.1 Without treatment 1.a.2 After on-site treatment 1.a.i To water resources 1.a.ii To the sea 1.b. To Sewerage (ISIC 37) 2. Reallocation of emission by ISIC 37 3. Net emissions (=1a+2) 1-3 30 25 5 1 26 5-33, 41-43 35 36 37 38,39, 45-99 Total 185 90 95 19 109 Households 185 Agriculture 30 Other industries Rest of the world 90 95 25 5 Sewerage 20 Water resources and the sea
Urban runoff Urban run-off: that portion of precipitation on urban areas that does not naturally percolate into the ground or evaporate, but flows via overland flow, underflow, or channels or is piped into a defined surface water channel or a constructed infiltration facility. It is generally highly polluted and there is an increasing awareness in the potential danger of discharging it into the environment without treatment. Emissions to water in the urban runoff are allocated to the Sewerage industry, ISIC 37 since this is the economic unit responsible for its collection and discharge
Conclusions Emission accounts are addressing new policy-relevant questions Existing data collection systems may contain useful information (e.g. Emissions Register) May need to set-up specific data collections Promotion of usefulness of (emission) accounts is very important. They will aide: Understanding of the costs and benefits of measures discussion with different stakeholders (e.g. agriculture versus industry as polluters of waters) monitoring of environmental efficiency definition of policy goals
PHYSICAL DATA ITEMS RELATED WITH WATER EMISSIONS
Wastewater Wastewater in SEEA is defined as all the water that is discarded and no longer required by the owner or user Wastewater by type of water users discharging > Household > Industries connected to sewer network > Sewage industries > Industries not connected to the sewer network > Agriculture > Thermoelectric plants > Hydroelectric plants
Data collection Common sources of data > Water and/or sewage utilities, companies, associations or regulators > Departments in charge of controlling polluting discharges (they may issue permits and develop inventories of polluting discharges) > National statistics office > Research institutions Data collection of wastewater should be done in conjunction with data collection of emissions
Waterborne polluting release Pollution problem > Transmission of disease through water > Reduction of dissolved oxygen in water > Proliferation of aquatic weed and algae > Poisoning of aquatic life and humans Emission statistics and accounts are based on the results of tests or analyses (e.g. BOD, COD, TSS) done to wastewater samples
Pollutants and their measurement Pollutants Parameters (Based on Laboratory Tests) Pathogenic viruses, bacteria, Fecal coliforms protozoa, and parasitic worms E. coli (helminthes) from excreta of Enterococci people with diseases. Organic Matter Biochemical oxygen demand (BOD) Chemical oxygen demand (COD) Total organic carbon (TOC) Nutrients Total Nitrogen (TN) Total Phosphorus (TP) Total Kjehldahl Nitrogen (TKN) Toxic substances that often accumulate through the food chain Tests to detect the presence of metals (e.g. Arsenic, Cadmium, Chromium) (E.g. metals, persistent organic pollutants, and cyanides). Also Tests to detect persistent organic pollutants (POPs), such as PCBs. known as micro-pollutants. Tests to detect cyanides. Substances that change the Total Solids (TS) physical properties of water. It Total suspended solids (TSS) includes a wide variety of Temperature properties that may reveal the Conductivity presence of pollutants. Acidity (ph) Color
Data items related with waterborne pollution Waterborne pollutant releases to other economic units (data item J) Sources of data: Data from wastewater utilities. Data processing required: Estimates of the different types of waterborne pollution released by economic activities and households to the sewer network. Pollution is measured using different parameters, usually based on laboratory tests of wastewaters. Relevant agencies: Wastewater or sewerage utilities. Ministry of Environment. Statistical projects to be developed: Inventory of wastewater treatment plants.
Waterborne pollutant emissions to the environment from point sources Sources of data: Estimates of waterborne pollution emitted to inland water resources, to the sea, or to land, by households and the different economic activities. Data processing required: Estimates of the different types of waterborne pollution released by economic activities and households. Amount of pollution retained in wastewater treatment plants based on treatment efficiencies reported by the wastewater treatment operators. Pollution is measured using different parameters, usually based on laboratory tests of wastewaters. Some pollution may be collected in sewer networks and the rest discharged directly to the environment. The waterborne pollution collected in sewer networks is also discharged to the environment with or without treatment. Relevant agencies: Wastewater utilities. Ministry of Environment. Statistical projects to be developed: Inventory of discharge points. Inventory of wastewater treatment plants.
Waterborne pollutant emissions to the environment from non-point sources (data item K.2) Sources of data: Estimates of waterborne pollution emitted to inland water resources, to the sea, or to land, by diffuse sources of pollution, such as the following: fertilizers, herbicides, and insecticides from agricultural lands; oil, grease, and toxic chemicals from urban runoff and energy production; organic matter from septic systems. Data processing required: Information about the amount of nitrogen and phosphorous applied to crops in the form of fertilizers. Relevant agencies: Ministry of Environment. Ministry of Agriculture (for non-point pollution emitted by agricultural activities). Statistical projects to be developed: Map of agricultural and industrial areas that discharge non-point pollution.
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